A technique related to a motor as a rotary machine has been proposed. For example, a permanent magnet motor is disclosed in Patent Literature 1. In this permanent magnet motor, an air gap of a rotation backward side portion of a portion facing a rotor surface of a tooth portion is larger than air gaps of other portions.
A method for manufacturing a molded motor is disclosed in Patent Literature 2. In this manufacturing method, wire is wound around a stator iron core including a ring-shaped yoke and a plurality of teeth that is arranged on the inner peripheral portion of the yoke, and the outer shell of the motor is formed by resin-integrated molding. This manufacturing method is characterized in that a clearance between the inner diameter of the stator iron core and the lower die inner core of the molding die is reduced to the minimum. Patent Literature 2 describes that the occurrence of thin-walled burr of resin in the inner diameter of the stator finished product formed by resin-integrated molding cannot be prevented and, in many cases, it is required to perform a process for removing a resin burr by additional work such as wire buffing or inner-diameter cutting in a post-process, and that, if this resin burr is not removed, the resin burr drops off during motor operation and becomes a factor to cause a motor sound failure.